Born in 1941, he graduated from ENA (French National School of Administration), Paris in 1966. He holds a masters degree in Public Law and a DEA in Sociology. After being the Environmental Advisor to the French Prime Minister from 1974 to 1977, he worked as the Director of Mission, Rural and Urban Environment, at the Ministry of the Environment. After having held several other leading posts at the Ministry of Environment, he joined the United Nations Environment Program in 1994. Former coordinator for the Mediterranean Action Plan and Secretary for the Barcelona Convention, Chabason acted as Consultant for OECD environmental evaluations of Portugal, Italy, the Netherlands, Sweden, Denmark, Ireland and Poland from 1993 to 2002. Chabason had also worked as Professor of Environmental Policy at the Institute of Political Sciences, Paris, 1990-1994.